Well done to you, I think I remember you? posting something a while back?
What's the difference in work load, are you not so hands on as you were? or are you talking about cleaning? but doing exactly the same job as you were when being a Caretaker, but better pay, good on you my friend.
Yes I feel the same as you, being taken for a mug, I would say more enthusiastic in our early days, a good job with respect and worth doing well, but we all live and learn.
Any way are you a proper site manager = one who does no cleaning, or is it just in name, as here in Suffolk we have 5 levels the higher the level the less cleaning you do, unfortunately I am only level 2 so a Caretaker who does 50% cleaning on 55p a hour more than the 2 cleaners we have here, but have no responsibility over them, I only order the stock and can get called off cleaning to do Caretaking duties. When you reach level 5 you are then classed as a proper site manager, but I will never reach that due to my age.
Anyway as said good luck to you, look after yourself and remember a favour today is your duty tomorrow.

I am a 'Premises Manager' I don't do much cleaning, only emergency spillages etc. More site security/safety based these days, obviously still hands on and get stuck in, bit of everything really (which is why i enjoy it). In my previous role as a 'Site Operative' at a MAT they had me doing everything for next to nothing! Complete joke.